Experiments will be performed on the one-kidney and two-kidney clip hypertension models to identify further differences between them. Medullary plasma flow will be investigated to determine whether there is reduction which could interfere with the production of the antihypertensive principle. Preliminary experiments will be carried out on a model of chronic renal failure, to study the development of hypertension, and to assess the roles of the renin-angiotensin system and volume expansion in this. Chronic glomerulonephritis will be produced in the rabbit by treatment with antiglomerular basement antibody. BIBLIOGRAPHIC REFERENCES: Renomedullary interstitial cell lesion and hypertension. Stuart, R., Salyer, W.R., Salyer, D.C., and Heptinstall, R.H. Human Pathology 7:327, 1976. Interstitial nephritis: a brief review. Heptinstall, R.H., Am. J. Pathol. 83:214, 1976.